This crosses Black’s plan, which involves capturing on e4 with the bishop and playing e7–e6 with a solid position.

Jones does not hurry with the sacrifice and prepares it with 7.Bc4. If 7.Nxf7 Kxf7 8.Ng5+ Ke8 9.Bc4 Bxg2 10.Rg1 Qe7! threatening Qb4+ winning the bishop on c4 is a clever defence.

It’s not at all easy to prevent White from embarking on a sacrificial attack. 7...Ngf6 8.Nxf7 Kxf7 9.Ng5+ Ke8 10.Nxe6 Qe7 11.0–0 Nb6 12.Re1 is a disaster for Black, who may have thought that 7...Bd5 prevented the sacrifice, but Jones is undeterred.